package org.dy.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class MBProperties extends java.util.Properties {

	private static final long serialVersionUID = 1L;

	private static final String keyValueSeparators = "=: \t\r\n\f";

	private static final String strictKeyValueSeparators = "=:";

	private static final String specialSaveChars = "=: \t\r\n\f#!";

	private static final String whiteSpaceChars = " \t\r\n\f";

	public synchronized void load(InputStream inStream, String encoding) throws IOException {
		BufferedReader in = new BufferedReader(new InputStreamReader(inStream, encoding));
		while (true) {
			// Get next line
			String line = in.readLine();
			if (line == null) {
				return;
			}

			if (line.length() > 0) {
				// Continue lines that end in slashes if they are not comments
				char firstChar = line.charAt(0);
				if ((firstChar != ' ') && (firstChar != '!')) {
					while (continueLine(line)) {
						String nextLine = in.readLine();
						if (nextLine == null) {
							nextLine = "";
						}
						String loppedLine = line
								.substring(0, line.length() - 1);
						// Advance beyond whitespace on new line
						int startIndex = 0;
						for (startIndex = 0; startIndex < nextLine.length(); startIndex++) {
							if (whiteSpaceChars.indexOf(nextLine
									.charAt(startIndex)) == -1) {
								break;
							}
						}
						nextLine = nextLine.substring(startIndex, nextLine
								.length());
						line = new String(loppedLine + nextLine);
					}

					// Find start of key
					int len = line.length();
					int keyStart;
					for (keyStart = 0; keyStart < len; keyStart++) {
						if (whiteSpaceChars.indexOf(line.charAt(keyStart)) == -1) {
							break;
						}
					}

					// Blank lines are ignored
					if (keyStart == len) {
						continue;
					}

					// Find separation between key and value
					int separatorIndex;
					for (separatorIndex = keyStart; separatorIndex < len; separatorIndex++) {
						char currentChar = line.charAt(separatorIndex);
						if (currentChar == '\\') {
							separatorIndex++;
						} else if (keyValueSeparators.indexOf(currentChar) != -1) {
							break;
						}
					}

					// Skip over whitespace after key if any
					int valueIndex;
					for (valueIndex = separatorIndex; valueIndex < len; valueIndex++) {
						if (whiteSpaceChars.indexOf(line.charAt(valueIndex)) == -1) {
							break;
						}
					}

					// Skip over one non whitespace key value separators if any
					if (valueIndex < len) {
						if (strictKeyValueSeparators.indexOf(line
								.charAt(valueIndex)) != -1) {
							valueIndex++;

							// Skip over white space after other separators if any
						}
					}
					while (valueIndex < len) {
						if (whiteSpaceChars.indexOf(line.charAt(valueIndex)) == -1) {
							break;
						}
						valueIndex++;
					}
					String key = line.substring(keyStart, separatorIndex);
					String value = (separatorIndex < len) ? line.substring(
							valueIndex, len) : "";

					// Convert then store key and value
					key = loadConvert(key);
					value = loadConvert(value);
					put(key, value);
				}
			}
		}
	}

	/*
	 * Returns true if the given line is a line that must
	 * be appended to the next line
	 */
	private boolean continueLine(String line) {
		int slashCount = 0;
		int index = line.length() - 1;
		while ((index >= 0) && (line.charAt(index--) == '\\'))
			slashCount++;
		return (slashCount % 2 == 1);
	}

	/*
	 * Converts encoded \\uxxxx to unicode chars
   * and changes special saved chars to their original forms
   */
	private String loadConvert(String theString) {
		char aChar;
		int len = theString.length();
		StringBuffer outBuffer = new StringBuffer(len);

		for (int x = 0; x < len;) {
			aChar = theString.charAt(x++);
			if (aChar == '\\') {
				aChar = theString.charAt(x++);
				if (aChar == 'u') {
					// Read the xxxx
					int value = 0;
					for (int i = 0; i < 4; i++) {
						aChar = theString.charAt(x++);
						switch (aChar) {
						case '0':
						case '1':
						case '2':
						case '3':
						case '4':
						case '5':
						case '6':
						case '7':
						case '8':
						case '9':
							value = (value << 4) + aChar - '0';
							break;
						case 'a':
						case 'b':
						case 'c':
						case 'd':
						case 'e':
						case 'f':
							value = (value << 4) + 10 + aChar - 'a';
							break;
						case 'A':
						case 'B':
						case 'C':
						case 'D':
						case 'E':
						case 'F':
							value = (value << 4) + 10 + aChar - 'A';
							break;
						default:
							throw new IllegalArgumentException(
									"Malformed \\uxxxx encoding.");
						}
					}
					outBuffer.append((char) value);
				} else {
					if (aChar == 't')
						aChar = '\t';
					else if (aChar == 'r')
						aChar = '\r';
					else if (aChar == 'n')
						aChar = '\n';
					else if (aChar == 'f')
						aChar = '\f';
					outBuffer.append(aChar);
				}
			} else
				outBuffer.append(aChar);
		}
		return outBuffer.toString();
	}

}